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Rigid Designator
In modal logic and the philosophy of language, a term is said to be a rigid designator or absolute substantial term when it designates (picks out, denotes, refers to) the same thing in ''all possible worlds'' in which that thing exists. A designator is ''persistently rigid'' if it also designates nothing in all other possible worlds. A designator is ''obstinately rigid'' if it designates the same thing in every possible world, period, whether or not that thing exists in that world. Rigid designators are contrasted with ''connotative terms'', ''non-rigid'' or ''flaccid designators'', which may designate different things in different possible worlds. History The Scholastic philosophers in the Middle Ages developed a theory of properties of terms in which different classifications of concepts feature prominently. Concepts, and the terms that signify them, can be divided into absolute or connotative, according to the mode in which they signify. If they signify something absolutely, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Modal Logic
Modal logic is a collection of formal systems developed to represent statements about necessity and possibility. It plays a major role in philosophy of language, epistemology, metaphysics, and natural language semantics. Modal logics extend other systems by adding unary operators \Diamond and \Box, representing possibility and necessity respectively. For instance the modal formula \Diamond P can be read as "possibly P" while \Box P can be read as "necessarily P". Modal logics can be used to represent different phenomena depending on what kind of necessity and possibility is under consideration. When \Box is used to represent epistemic necessity, \Box P states that P is epistemically necessary, or in other words that it is known. When \Box is used to represent deontic necessity, \Box P states that P is a moral or legal obligation. In the standard relational semantics for modal logic, formulas are assigned truth values relative to a '' possible world''. A formula's truth value ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Definite Descriptions
In formal semantics and philosophy of language, a definite description is a denoting phrase in the form of "the X" where X is a noun-phrase or a singular common noun. The definite description is ''proper'' if X applies to a unique individual or object. For example: " the first person in space" and " the 42nd President of the United States of America", are proper. The definite descriptions "the person in space" and "the Senator from Ohio" are ''improper'' because the noun phrase X applies to more than one thing, and the definite descriptions "the first man on Mars" and "the Senator from some Country" are ''improper'' because X applies to nothing. Improper descriptions raise some difficult questions about the law of excluded middle, denotation, modality, and mental content. Russell's analysis As France is currently a republic, it has no king. Bertrand Russell pointed out that this raises a puzzle about the truth value of the sentence "The present King of France is bald." The sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counterpart Theory
In philosophy, specifically in the area of metaphysics, counterpart theory is an alternative to standard ( Kripkean) possible-worlds semantics for interpreting quantified modal logic. Counterpart theory still presupposes possible worlds, but differs in certain important respects from the Kripkean view. The form of the theory most commonly cited was developed by David Lewis, first in a paper and later in his book '' On the Plurality of Worlds''. Differences from the Kripkean view Counterpart theory (hereafter "CT"), as formulated by Lewis, requires that individuals exist in only one world. The standard account of possible worlds assumes that a modal statement about an individual (e.g., "it is possible that x is y") means that there is a possible world, W, where the individual x has the property y; in this case there is only one individual, x, at issue. On the contrary, counterpart theory supposes that this statement is really saying that there is a possible world, W, wherein exists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instantiation Principle
The instantiation principle or principle of instantiation or principle of exemplification is the concept in metaphysics and logic (first put forward by David Malet Armstrong) that there can be no uninstantiated or unexemplified properties (or universals In metaphysics, a universal is what particular things have in common, namely characteristics or qualities. In other words, universals are repeatable or recurrent entities that can be instantiated or exemplified by many particular things. For exa ...). In other words, it is impossible for a property to exist which is not had by some object. Consider a chair. Presumably chairs did not exist 150,000 years ago. Thus, according to the principle of instantiation, the property of being a chair did not exist 150,000 years ago either. Similarly, if all red objects were to suddenly go out of existence, then the property of being red would likewise go out of existence. To make the principle more plausible in the light of these examples, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (philosophy)
A class is a collection whose members either fall under a predicate or are classified by a rule. Hence, while a set can be extensionally defined only by its elements, a class has also an intensional dimension that unite its members. When the term 'class' is applied such that it includes those sets elements of which are intended to be collected without a common predicate or rule, the distinction can be indicated by calling such sets "improper class." Philosophers sometimes distinguish classes from types and kinds. We can talk about the ''class'' of human beings, just as we can talk about the ''type'' (or ''natural kind''), human being, or humanity. How, then, might classes differ from types? One might well think they are not actually different categories of being, but typically, while both are treated as abstract objects, classes are not usually treated as universals, whereas types usually are. Whether natural kinds ought to be considered universals is vexed; see natural k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Necessity Of Identities
In modal logic, the necessity of identity is the thesis that for every object x and object y, if x and y are the same object, it is necessary that x and y are the same object. The thesis is best known for its association with Saul Kripke, who published it in 1971, although it was first derived by the logician Ruth Barcan Marcus in 1947, and later, in simplified form, by W. V. O. Quine in 1953. Kripke's derivation The derivation in Kripke's 'Identity and Necessity' is in three steps: :(1) \forall x \Box (x = x). :(2) \forall x \forall y(x = y \to (\Box (x = x) \to \Box (x = y))). :(3) \forall x \forall y(x = y \to \Box (x = y)) The first premise is simply postulated: every object is identical to itself. The second is an application of the principle of substitutivity: if a = b, then a has all the properties b has, thus from Fa, infer Fb, where F is \Box (a = \_). The third follows by elementary predicate logic. Rigid designation In the later ''Naming and Necessity'', Kripke sug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a solvent). It is vital for all known forms of life, despite not providing food energy, food, energy or organic micronutrients. Its chemical formula, H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is also the name of the liquid state of H2O at standard temperature and pressure. A number of natural states of water exist. It forms precipitation in the form of rain and aerosols in the form of fog. Clouds consist of suspended droplets of water and ice, its solid state. When finely divided, crystalline ice may precipitate in the form of snow. The gaseous state of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Causal Theory Of Reference
A causal theory of reference or historical chain theory of reference is a theory of how terms acquire specific referents based on evidence. Such theories have been used to describe many referring terms, particularly logical terms, proper names, and natural kind terms. In the case of names, for example, a causal theory of reference typically involves the following claims: * a name's referent is fixed by an original act of naming (also called a "dubbing" or, by Saul Kripke, an "initial baptism"), whereupon the name becomes a rigid designator of that object. * later uses of the name succeed in referring to the referent by being linked to that original act via a causal chain. Weaker versions of the position (perhaps not properly called "causal theories"), claim merely that, in many cases, events in the causal history of a speaker's use of the term, including when the term was first acquired, must be considered to correctly assign references to the speaker's words. Causal theories of n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johnny Depp
John Christopher Depp II (born June 9, 1963) is an American actor and musician. He is the recipient of List of awards and nominations received by Johnny Depp, multiple accolades, including a Golden Globe Award and a Screen Actors Guild Award, in addition to nominations for three Academy Awards and two British Academy Film Awards, BAFTA awards. Depp made his feature film debut in the horror film ''A Nightmare on Elm Street'' (1984) and appeared in ''Platoon (film), Platoon'' (1986), before rising to prominence as a teen idol on the television series ''21 Jump Street'' (1987–1990). In the 1990s, Depp acted mostly in independent films with auteur directors, often playing eccentric characters. These included ''Cry-Baby'' (1990), ''What's Eating Gilbert Grape'' (1993), ''Benny and Joon'' (1993), ''Dead Man'' (1995), ''Donnie Brasco (film), Donnie Brasco'' (1997), and ''Fear and Loathing in Las Vegas (film), Fear and Loathing in Las Vegas'' (1998). Depp also began his longtime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Essentialism
Scientific essentialism, a view espoused by Saul Kripke and Hilary Putnam, maintains that there exist essential properties that objects possess (or instantiate) necessarily. In other words, having such and such essential properties is a necessary condition for membership in a given natural kind. For example, tigers are tigers in virtue of possessing a particular set of genetic properties, but identifying (or appearance-based) properties are nonessential properties. If a tiger lost a leg, or didn't possess stripes, we would still call it a tiger. They are not necessary for being a member of the class of tigers. It is important, however, that the set of essential properties of an object not be used to identify or be identified with that object because they are not ''necessary and sufficient'', but only necessary. Having such and such a genetic code does not suffice for being a tiger. We wouldn't call a piece of tiger tail a tiger, even though a piece of tiger tail contains the gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy (biology)
In biology, taxonomy () is the scientific study of naming, defining ( circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon) and these groups are given a taxonomic rank; groups of a given rank can be aggregated to form a more inclusive group of higher rank, thus creating a taxonomic hierarchy. The principal ranks in modern use are domain, kingdom, phylum (''division'' is sometimes used in botany in place of ''phylum''), class, order, family, genus, and species. The Swedish botanist Carl Linnaeus is regarded as the founder of the current system of taxonomy, as he developed a ranked system known as Linnaean taxonomy for categorizing organisms and binomial nomenclature for naming organisms. With advances in the theory, data and analytical technology of biological systematics, the Linnaean system has transformed into a system of modern biological classification intended to reflect the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Kind
"Natural kind" is an intellectual grouping, or categorizing of things, in a manner that is reflective of the actual world and not just human interests. Some treat it as a classification identifying some structure of truth and reality that exists whether or not humans recognize it. Others treat it as intrinsically useful to the human mind, but not necessarily reflective of something more objective. Candidates examples of natural kinds are found in all the sciences, but the field of chemistry provides the paradigm example of elements. John Dewey held a minority view that belief in unconditional natural kinds is a mistake, a relic of obsolete scientific practices. W. V. O. Quine and Hilary Kornblith held the majoirity view that natural kinds are the unchanging structure of truth and reality. Hilary Putnam rejects descriptivist approaches to natural kinds with semantic reasoning. Hasok Chang and Rasmus Winther hold the emerging view that natural kinds are useful and evolving scientif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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